body{
    height: 700px;
}
ul,li{
    list-style: none;
}
#container{
    width: 700px;
    height: 490px;
    position: relative;
    overflow: hidden;
    border-radius: 10px;
}
.item{
    position: absolute;
}
.item img{
    width: 100%;
    height: 100%;
}
#tabs{
    position: absolute;
    right: 30px;
    bottom: 30px;
}
.tab{
    float: left;
    margin-right: 30px;
    width: 6px;
    height: 6px;
    background-color: #989196;
    border: 3px solid rgba(141, 124, 135, 0.8);
    border-radius: 50%;
    cursor: pointer;
}
.active{
    background-color: #fff;
    border-color: #999487;
}
.btn{
    position: absolute;
    width: 40px;
    height: 70px;
    color: #d6d3d5;
    font-size: 36px;
    line-height: 70px;
    text-align: center;
    cursor: pointer;
    top: 210px;
}
.prev{
    left: 10px;
}
.next{
    right: 10px;
}
.btn:hover{
    background-color: rgba(127,120,125,0.8);
    border-radius: 10px;
}
#back{
    width: 50px;
    height: 50px;
    background-color: #000;
    color: #fff;
    font-size: 55px;
    border-radius: 10px;
    text-align: center;
    position: fixed;
    right: 50px;
    bottom: 10px;
    background-repeat: no-repeat;
}